You should NOT change any W-2 information. The IRS gets a copy from the employer and what you report must match. In addition if the W-2 box 1 amount is less the the box 3 amount the difference must be accounted for in box 12 - if not, that could be a "red-flag" audit trigger.
TurboTax has released a FAQ on this issue - scheduled for 4/5/2019
Excess 401(k) Contribution Preventing e-File
https://ttlc.intuit.com/replies/7327357
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**